System File Chooser: (PR #988)

- fixed missing filter in combobox if only `setFileFilter(myFilter)` is used, but not `addChoosableFileFilter(myFilter)`
- fallback Swing file chooser did ignore `isAcceptAllFileFilterUsed()`
- check for supported filter types in `setFileFilter()`

flatlaf-core/src/main/java/com/formdev/flatlaf/util/SystemFileChooser.java

@@ -24,7 +24,9 @@ import java.awt.Window;
 import java.io.File;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicReference;
@@ -367,12 +369,23 @@ public class SystemFileChooser
 		setApproveButtonMnemonic( vk );
 	}
 
-	/** @see JFileChooser#getFileSelectionMode() */
+	/**
+	 * Returns file-selection mode.
+	 * Possible values are {@link #FILES_ONLY} and {@link #DIRECTORIES_ONLY}.
+	 * Default is {@link #FILES_ONLY}.
+	 *
+	 * @see JFileChooser#getFileSelectionMode()
+	 */
 	public int getFileSelectionMode() {
 		return fileSelectionMode;
 	}
 
-	/** @see JFileChooser#setFileSelectionMode(int) */
+	/**
+	 * Sets file-selection mode.
+	 * Possible values are {@link #FILES_ONLY} and {@link #DIRECTORIES_ONLY}.
+	 *
+	 * @see JFileChooser#setFileSelectionMode(int)
+	 */
 	public void setFileSelectionMode( int fileSelectionMode ) {
 		if( fileSelectionMode != FILES_ONLY && fileSelectionMode != DIRECTORIES_ONLY )
 			throw new IllegalArgumentException( "Invalid file selection mode " + fileSelectionMode );
@@ -488,8 +501,7 @@ public class SystemFileChooser
 		if( filter == null || filters.contains( filter ) )
 			return;
 
-		if( !(filter instanceof FileNameExtensionFilter) && !(filter instanceof AcceptAllFileFilter) )
+		checkSupportedFileFilter( filter );
-			throw new IllegalArgumentException( "Filter class not supported: " + filter.getClass().getName() );
 
 		// either insert filter before "All Files" filter, or append to the end
 		int size = filters.size();
@@ -559,15 +571,35 @@ public class SystemFileChooser
 
 	/** @see JFileChooser#setFileFilter(javax.swing.filechooser.FileFilter) */
 	public void setFileFilter( FileFilter filter ) {
+		checkSupportedFileFilter( filter );
+
 		this.fileFilter = filter;
 	}
 
-	private int indexOfCurrentFilter() {
+	private void checkSupportedFileFilter( FileFilter filter ) throws IllegalArgumentException {
-		return filters.indexOf( fileFilter );
+		if( filter == null ||
+			filter instanceof FileNameExtensionFilter ||
+			filter instanceof AcceptAllFileFilter )
+		  return;
+
+		throw new IllegalArgumentException( "Filter class not supported: " + filter.getClass().getName() );
 	}
 
-	private boolean hasOnlyAcceptAll() {
+	private List<FileFilter> getFiltersForDialog() {
-		return filters.size() == 1 && filters.get( 0 ) == getAcceptAllFileFilter();
+		// has only accept-all filter
+		if( filters.size() == 1 &&
+			filters.get( 0 ) == getAcceptAllFileFilter() &&
+			(fileFilter == getAcceptAllFileFilter() || fileFilter == null) )
+		  return Collections.emptyList();
+
+		// check whether current filter is already in list
+		if( (fileFilter != null && filters.contains( fileFilter )) || fileFilter == null )
+			return filters;
+
+		// add current file filter to list
+		List<FileFilter> filters2 = new ArrayList<>( filters );
+		filters2.add( 0, fileFilter );
+		return filters2;
 	}
 
 	public ApproveCallback getApproveCallback() {
@@ -854,9 +886,10 @@ public class SystemFileChooser
 			int fileTypeIndex = 0;
 			ArrayList<String> fileTypes = new ArrayList<>();
 			if( !fc.isDirectorySelectionEnabled() ) {
-				if( !fc.hasOnlyAcceptAll() ) {
+				List<FileFilter> filters = fc.getFiltersForDialog();
-					fileTypeIndex = fc.indexOfCurrentFilter();
+				if( !filters.isEmpty() ) {
-					for( FileFilter filter : fc.getChoosableFileFilters() ) {
+					fileTypeIndex = filters.indexOf( fc.getFileFilter() );
+					for( FileFilter filter : filters ) {
 						if( filter instanceof FileNameExtensionFilter ) {
 							fileTypes.add( filter.getDescription() );
 							fileTypes.add( "*." + String.join( ";*.", ((FileNameExtensionFilter)filter).getExtensions() ) );
@@ -975,9 +1008,11 @@ public class SystemFileChooser
 			// filter
 			int fileTypeIndex = 0;
 			ArrayList<String> fileTypes = new ArrayList<>();
-			if( !fc.isDirectorySelectionEnabled() && !fc.hasOnlyAcceptAll() ) {
+			if( !fc.isDirectorySelectionEnabled() ) {
-				fileTypeIndex = fc.indexOfCurrentFilter();
+				List<FileFilter> filters = fc.getFiltersForDialog();
-				for( FileFilter filter : fc.getChoosableFileFilters() ) {
+				if( !filters.isEmpty() ) {
+					fileTypeIndex = filters.indexOf( fc.getFileFilter() );
+					for( FileFilter filter : filters ) {
 						if( filter instanceof FileNameExtensionFilter ) {
 							fileTypes.add( filter.getDescription() );
 							for( String ext : ((FileNameExtensionFilter)filter).getExtensions() )
@@ -990,6 +1025,7 @@ public class SystemFileChooser
 						}
 					}
 				}
+			}
 
 			// callback
 			FlatNativeMacLibrary.FileChooserCallback callback = (fc.getApproveCallback() != null)
@@ -1090,9 +1126,11 @@ public class SystemFileChooser
 			// filter
 			int fileTypeIndex = 0;
 			ArrayList<String> fileTypes = new ArrayList<>();
-			if( !fc.isDirectorySelectionEnabled() && !fc.hasOnlyAcceptAll() ) {
+			if( !fc.isDirectorySelectionEnabled() ) {
-				fileTypeIndex = fc.indexOfCurrentFilter();
+				List<FileFilter> filters = fc.getFiltersForDialog();
-				for( FileFilter filter : fc.getChoosableFileFilters() ) {
+				if( !filters.isEmpty() ) {
+					fileTypeIndex = filters.indexOf( fc.getFileFilter() );
+					for( FileFilter filter : filters ) {
 						if( filter instanceof FileNameExtensionFilter ) {
 							fileTypes.add( filter.getDescription() );
 							for( String ext : ((FileNameExtensionFilter)filter).getExtensions() )
@@ -1105,6 +1143,7 @@ public class SystemFileChooser
 						}
 					}
 				}
+			}
 
 			// callback
 			FlatNativeLinuxLibrary.FileChooserCallback callback = (fc.getApproveCallback() != null)
@@ -1202,6 +1241,7 @@ public class SystemFileChooser
 			chooser.setFileSelectionMode( fc.getFileSelectionMode() );
 			chooser.setMultiSelectionEnabled( fc.isMultiSelectionEnabled() );
 			chooser.setFileHidingEnabled( fc.isFileHidingEnabled() );
+			chooser.setAcceptAllFileFilterUsed( fc.isAcceptAllFileFilterUsed() );
 
 			// system file dialogs do not support multi-selection for Save File dialogs
 			if( chooser.isMultiSelectionEnabled() &&
@@ -1210,24 +1250,21 @@ public class SystemFileChooser
 			  chooser.setMultiSelectionEnabled( false );
 
 			// filter
-			if( !fc.isDirectorySelectionEnabled() && !fc.hasOnlyAcceptAll() ) {
+			if( !fc.isDirectorySelectionEnabled() ) {
+				List<FileFilter> filters = fc.getFiltersForDialog();
+				if( !filters.isEmpty() ) {
 					FileFilter currentFilter = fc.getFileFilter();
-				for( FileFilter filter : fc.getChoosableFileFilters() ) {
+					chooser.removeChoosableFileFilter( chooser.getAcceptAllFileFilter() );
+					for( FileFilter filter : filters ) {
 						javax.swing.filechooser.FileFilter jfilter = convertFilter( filter, chooser );
 						if( jfilter == null )
 							continue;
 
 						chooser.addChoosableFileFilter( jfilter );
-					if( filter == currentFilter ) {
+						if( filter == currentFilter )
 							chooser.setFileFilter( jfilter );
-						currentFilter = null;
 					}
 				}
-				if( currentFilter != null ) {
-					javax.swing.filechooser.FileFilter jfilter = convertFilter( currentFilter, chooser );
-					if( jfilter != null )
-						chooser.setFileFilter( jfilter );
-				}
 			}
 
 			// paths